AzureFunctions.TestFramework.Blob 0.14.0

AzureFunctions.TestFramework.Blob

👁 NuGet

BlobTrigger and BlobInput support for the Azure Functions Test Framework. Provides:

• InvokeBlobAsync(...) — trigger blob-triggered functions directly from tests.
• WithBlobInputContent(...) — inject fake blob content for functions that use [BlobInput] (non-trigger input binding).

BlobTrigger invocation

using AzureFunctions.TestFramework.Blob;
using AzureFunctions.TestFramework.Core;

public class BlobFunctionTests : IAsyncLifetime
{
 private IFunctionsTestHost _testHost;

 public async Task InitializeAsync()
 {
 _testHost = await new FunctionsTestHostBuilder()
 .WithFunctionsAssembly(typeof(MyBlobFunction).Assembly)
 .BuildAndStartAsync();
 }

 [Fact]
 public async Task ProcessBlob_WithTextContent_Succeeds()
 {
 var content = BinaryData.FromString("Hello from blob!");
 var result = await _testHost.InvokeBlobAsync("ProcessBlob", content, blobName: "test/file.txt");
 Assert.True(result.Success);
 }

 [Fact]
 public async Task ProcessBlob_WithJsonContent_Succeeds()
 {
 var content = BinaryData.FromObjectAsJson(new { id = "123", name = "test" });
 var result = await _testHost.InvokeBlobAsync(
 "ProcessBlob", content,
 blobName: "orders/order-123.json",
 containerName: "orders");
 Assert.True(result.Success);
 }

 public async Task DisposeAsync()
 {
 await _testHost.StopAsync();
 _testHost.Dispose();
 }
}

[BlobInput] injection

The WithBlobInputContent builder extension injects fake blob content for functions that use the [BlobInput] attribute (non-trigger input binding).

// Function under test
[Function("ReadDocument")]
public static string Run(
 [QueueTrigger("process-queue")] string blobPath,
 [BlobInput("documents/template.txt")] string templateContent)
{
 return $"Template: {templateContent}";
}

// Test setup
using AzureFunctions.TestFramework.Blob;

_testHost = await new FunctionsTestHostBuilder()
 .WithFunctionsAssembly(typeof(MyFunction).Assembly)
 // Register the content to inject for [BlobInput("documents/template.txt")]
 .WithBlobInputContent("documents/template.txt", BinaryData.FromString("Hello, template!"))
 .BuildAndStartAsync();

Multiple blobs: Use the dictionary overload to register several paths at once:

_testHost = await new FunctionsTestHostBuilder()
 .WithFunctionsAssembly(typeof(MyFunction).Assembly)
 .WithBlobInputContent(new Dictionary<string, BinaryData>
 {
 ["documents/template.txt"] = BinaryData.FromString("Hello, template!"),
 ["configs/settings.json"] = BinaryData.FromObjectAsJson(new { timeout = 30 }),
 })
 .BuildAndStartAsync();

The blobPath key must match the path declared in the [BlobInput] attribute exactly (case-insensitive). Dynamic path templates (e.g. "documents/{queueTrigger}") are matched against the template string, not the resolved path. When no content is registered for a binding, an empty byte[] is injected (which the worker surfaces as null / empty for string and stream parameters).

Supported parameter types: string, byte[], Stream, BinaryData, ReadOnlyMemory<byte>. For SDK client types (BlobClient, BlockBlobClient, etc.), see the sections below.

BlobTrigger with BlobClient parameter

When a blob-triggered function receives a BlobClient (or BlockBlobClient, PageBlobClient, etc.) instead of content bytes, register a BlobServiceClient on the test host and use the container/blob overload:

using Azure.Storage.Blobs;
using AzureFunctions.TestFramework.Blob;

_testHost = await new FunctionsTestHostBuilder()
 .WithFunctionsAssembly(typeof(MyBlobFunction).Assembly)
 .WithBlobServiceClient(new BlobServiceClient("UseDevelopmentStorage=true"))
 .BuildAndStartAsync();

// Invoke with container and blob name — the function receives a BlobClient
var result = await _testHost.InvokeBlobAsync("ProcessBlobClient", "my-container", "my-blob.txt");
Assert.True(result.Success);

[BlobInput] with BlobClient parameter

For [BlobInput] bindings targeting SDK client types, also register the blob path with WithBlobInputClient:

_testHost = await new FunctionsTestHostBuilder()
 .WithFunctionsAssembly(typeof(MyFunction).Assembly)
 .WithBlobServiceClient(new BlobServiceClient("UseDevelopmentStorage=true"))
 .WithBlobInputClient("my-container/data.txt")
 .BuildAndStartAsync();

Supported client parameter types: BlobClient, BlockBlobClient, PageBlobClient, AppendBlobClient, BlobBaseClient, BlobContainerClient.

References

• Full documentation
• AzureFunctions.TestFramework.Core

License

MIT